Blank subframe uplink design

ABSTRACT

Blank subframe link design uses reduced bandwidth either explicit or derived for Closed Subscriber Group (CSG) cell interference mitigation, enabling a non-allowed User Equipment (UE) to co-exist with CSG cells on the same carrier. One could specify UL blank subframes to orthogonalize non-allowed UE and allowed UE transmissions on UL either via explicit UL blank subframe definition or derived from DL blank subframe definition. Scheduling can orthogonalize data transmissions. A femto cell temporarily reducing uplink bandwidth can mitigate uplink control channel residual interference from a non-allowed UE. A relay configures RACH occasion to coincide with non-blank UL subframes as much as possible. UE knowledge of RACH occasion is sufficient to start RACH and hand over procedure. RACH occasions with 10 ms periodicity are supported by assigning all odd/even uplink HARQ interlaces to relay. RACH occasions with 20 ms periodicity are supported by assigning any of the ¼ UL HARQ interlaces to relay.

CLAIM OF PRIORITY UNDER 35 U.S.C. §119 AND §120

The present application is a Continuation application of U.S. Ser. No.12/626,236, filed Nov. 25, 2009, entitled “Blank Subframe Uplink Design”which claims priority to Provisional Application No. 61/118,891 entitled“Blank Subframe Uplink Design” filed Dec. 1, 2008, and assigned to theassignee hereof and hereby expressly incorporated by reference herein.

BACKGROUND

1. Field

The present disclosure relates generally to communication, and morespecifically for scheduling in a wireless communication network.

2. Background

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, data, and so on. Thesesystems may be multiple access systems capable of supportingcommunication with multiple users by sharing the available systemresources (e.g., bandwidth and transmit power). Examples of suchmultiple access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, and orthogonal frequencydivision multiple access (OFDMA) systems.

Generally, a wireless multiple access communication system cansimultaneously support communication for multiple wireless terminals.Each terminal communicates with one or more base stations viatransmissions on the forward and reverse links. The forward link (ordownlink) refers to the communication link from the base stations to theterminals, and the reverse link (or uplink) refers to the communicationlink from the terminals to the base stations. This communication linkmay be established via a single-input-single-output (SISO),multiple-input-single-output (MISO), single-input-multiple-output (SIMO)or a multiple-input-multiple-output (MIMO) system.

Universal Mobile Telecommunications System (UMTS) is one of thethird-generation (3G) cell phone technologies. UTRAN, short for UMTSTerrestrial Radio Access Network, is a collective term for the basenodes (Node B's) and Radio Network Controllers (RNC) which make up theUMTS core network. This communications network can carry many traffictypes, from real-time Circuit Switched to IP based Packet Switched. TheUTRAN allows connectivity between the UE (user equipment) and the corenetwork. The UTRAN contains the base stations, which are called Node Bs,and RNCs. The RNC provides control functionalities for one or more NodeBs. A Node B and an RNC can be the same device, although typicalimplementations have a separate RNC located in a central office servingmultiple Node B's. Despite the fact that they do not have to bephysically separated, there is a logical interface between them known asthe Iub. The RNC and its corresponding Node Bs are called the RadioNetwork Subsystem (RNS). There can be more than one RNS present in anUTRAN.

Third Generation Partnership Project (3GPP) LTE (Long Term Evolution) isthe name given to a project within the 3GPP to improve the UMTS mobilephone standard to cope with future requirements. Goals include improvingefficiency, lowering costs, improving services, making use of a newspectrum of opportunities, and better integration with other openstandards. The LTE system is described in the Evolved UTRA (EUTRA) andEvolved UTRAN (EUTRAN) series of specifications. In order to provideimproved communication services and increased efficiency, cellularcommunication systems are continuously developed and enhanced.Currently, the 3rd Generation Partnership Project (3GPP) standards bodyis in the process of standardizing improvements to the Universal MobileTelecommunication System (UMTS) known as LTE.

Similarly, to advanced communication services, such as High SpeedDownlink Packet Access (HSDPA) and High Speed Uplink Packet Access(HSUPA), LTE uses a very fast scheduling of communication resourcesallocated to user traffic and control data over the air interface.Specifically, scheduling for user traffic may be performed in theindividual serving base station (eNodeB) thereby allowing scheduling tobe so fast that it can follow changes in the characteristics of thepropagation channels to the individual User Equipments (UEs). This isused to schedule data for UEs such that data is predominantly scheduledfor UEs which currently experience advantageous propagation conditions.The fast scheduling may be performed both for uplink user data traffictransmitted on a physical channel known as the Physical Uplink SharedCHannel (PUSCH) and for downlink user data traffic transmitted on aphysical channel known as the Physical Downlink Shared CHannel (PDSCH).

In LTE, the resource allocation can be changed in sub-frames having aduration of only 1 ms with a typical scheduling interval (i.e., howoften the scheduling algorithm runs) of between 1 and 10 sub-frames. Oneframe consists of 10 such consecutive sub-frames. The PUSCH and PDSCHare shared channels wherein the scheduling is not only dependent on thecurrent propagation conditions but also on the resource requirement ofthe UEs. In order to simplify the scheduling and to reduce the signalingoverhead, LTE allows for persistent scheduling wherein a resourceallocation for the PUSCH or PDSCH may be made for a plurality ofsubframes.

In order to provide efficient fast scheduling in the base station, theUE must transmit uplink control information to the scheduling basestation. Specifically, the UE transmits Channel Quality Indicator (CQI)data which is indicative of the current propagation conditions for theUE. Based on the measurements of the received signal, the UE generates aCQI which may indicate a modulation scheme and data rate that isconsidered to be supportable by the air interface communication channelfrom the base station to the UE, or which may be a measure of the Signalto Noise plus Interference Ratio. As another example, LTE uses aretransmission scheme (referred to as Automatic Repeat reQuest (ARQ) orHybrid ARQ (HARQ)) and the UE transmits ARQ data in the form of uplinkacknowledge (ACK) or non-acknowledge (NACK) messages which are used todetermine whether individual data packets need to be retransmitted. Asyet another example, LTE allows the base station to utilize adaptiveantenna technology and the UE may report a Precoding Matrix Index (PMI)which is used to signal the antenna weights recommended by the UE forthe individual antenna elements.

The uplink control information is transmitted using physical uplinkchannels. Specifically, in sub-frames wherein the UE transmits uplinkuser data traffic on the PUSCH, the control data is embedded within thetransmission such that the control information is transmitted to thebase station using the PUSCH. However, for sub-frames wherein no uplinkuser data traffic is transmitted on the PUSCH, the UE uses a physicaluplink channel known as the Physical Uplink Control CHannel (PUCCH) totransmit the control information. Thus, the physical air interfacechannel used for the transmission of the control information may changefor different sub-frames.

SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the disclosed aspects. This summary isnot an extensive overview and is intended to neither identify key orcritical elements nor delineate the scope of such aspects. Its purposeis to present some concepts of the described features in a simplifiedform as a prelude to the more detailed description that is presentedlater.

In one aspect, a method is provided for interference mitigation in awireless communication system by employing a processor executingcomputer executable instructions stored on a computer readable storagemedium to implement the following acts: A half duplex schedule ofperforming non-simultaneous receiving and transmitting by a relay withan access node is determined. A physical random access channelconfiguration is determined having a random access channel occasion thatcoincides with the half duplex schedule. A random access channelprocedure is performed with the access node via the relay by using thephysical random access channel configuration.

In another aspect, a computer program product is provided forinterference mitigation in a wireless communication system. At least onecomputer readable storage medium stores computer executable instructionsthat, when executed by at least one processor, implement components: Afirst set of codes determines a half duplex schedule of performingnon-simultaneous receiving and transmitting by a relay with an accessnode. A second set of codes determines a physical random access channelconfiguration having a random access channel occasion that coincideswith the half duplex schedule. A third set of codes performs a randomaccess channel procedure with the access node via the relay by using thephysical random access channel configuration.

In an additional aspect, an apparatus is provided for interferencemitigation in a wireless communication system. At least one computerreadable storage medium stores computer executable instructions that,when executed by the at least one processor, implement components: Meansare provided for determining a half duplex schedule of performingnon-simultaneous receiving and transmitting by a relay with an accessnode. Means are provided for determining a physical random accesschannel configuration having a random access channel occasion thatcoincides with the half duplex schedule. Means are provided forperforming a random access channel procedure with the access node viathe relay by using the physical random access channel configuration.

In a further aspect, an apparatus is provided for interferencemitigation in a wireless communication system. A computing platformdetermines a half duplex schedule of performing non-simultaneousreceiving and transmitting by a relay with an access node and determinesa physical random access channel configuration having a random accesschannel occasion that coincides with the half duplex schedule. Atransmitter and a receiver perform a random access channel procedurewith the access node via the relay by using the physical random accesschannel configuration.

In yet one aspect, a method is provided for interference mitigation in awireless communication system by employing a processor executingcomputer executable instructions stored on a computer readable storagemedium to implement the following acts: A user equipment is scheduled touse an uplink having a first bandwidth. A band edge portion of the firstbandwidth is defined that includes an interference signal. A reducedportion of an uplink bandwidth is scheduled to the user equipment thatavoids the band edge portion. The reduced portion of the uplinkbandwidth is received by filtering out the band edge portion.

In yet another aspect, a computer program product is provided forinterference mitigation in a wireless communication system. At least onecomputer readable storage medium stores computer executable instructionsthat, when executed by at least one processor, implement components: Afirst set of codes schedules a user equipment to use an uplink having afirst bandwidth. A second set of codes defines a band edge portion ofthe first bandwidth that includes an interference signal. A third set ofcodes schedules a reduced portion of an uplink bandwidth to the userequipment that avoids the band edge portion. A fourth set of codesreceives the reduced portion of the uplink bandwidth by filtering outthe band edge portion.

In yet an additional aspect, an apparatus is provided for interferencemitigation in a wireless communication system. At least one computerreadable storage medium stores computer executable instructions that,when executed by the at least one processor, implement components: Meansare provided for scheduling a user equipment to use an uplink having afirst bandwidth. Means are provided for defining a band edge portion ofthe first bandwidth that includes an interference signal. Means areprovided for scheduling a reduced portion of an uplink bandwidth to theuser equipment that avoids the band edge portion. Means are provided forreceiving the reduced portion of the uplink bandwidth by filtering outthe band edge portion.

In yet a further aspect, an apparatus is provided for interferencemitigation in a wireless communication system. A scheduler schedules auser equipment via a transmitter to use an uplink having a firstbandwidth. A computing platform defines a band edge portion of the firstbandwidth that includes an interference signal. The scheduler furtherschedules a reduced portion of an uplink bandwidth via the transmitterto the user equipment that avoids the band edge portion. A receiverreceives the reduced portion of the uplink bandwidth by filtering outthe band edge portion.

To the accomplishment of the foregoing and related ends, one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative aspectsand are indicative of but a few of the various ways in which theprinciples of the aspects may be employed. Other advantages and novelfeatures will become apparent from the following detailed descriptionwhen considered in conjunction with the drawings and the disclosedaspects are intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, nature, and advantages of the present disclosure willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout and wherein:

FIG. 1A illustrates a node that performs interference mitigation in aheterogeneous wireless network by reducing uplink bandwidth.

FIG. 1B illustrates a block diagram of a user equipment performing ahandover with a node via a relay that uses half-duplex transmission andreception.

FIG. 2 illustrates a diagram of a wireless communication systemconfigured to support a number of users.

FIG. 3 illustrates a diagram of a wireless communication systemcomprising macro cells, femto cells and pico cells.

FIG. 4 illustrates a diagram of a communication system where one or morefemto nodes are deployed within a network environment.

FIG. 5 illustrates a diagram of a coverage map where several trackingareas, routing areas or location areas are defined.

FIG. 6 illustrates a diagram of a multiple access wireless communicationsystem.

FIG. 7 illustrates a schematic of a multiple input multiple output(MIMO) communication system.

FIG. 8 illustrates a flow diagram of a methodology or sequence ofoperations for interference mitigation in a wireless communicationsystem.

FIG. 9 illustrates a flow diagram of a methodology or sequence ofoperations for interference mitigation in a heterogeneous wirelesscommunication system.

FIG. 10 illustrates a block diagram of a logical grouping of electricalcomponents for interference mitigation in a wireless communicationsystem that is incorporated at least in part in a user equipment.

FIG. 11 illustrates a block diagram of a logical grouping of electricalcomponents for interference mitigation in a heterogeneous wirelesscommunication system that is incorporated at least in part in a node.

FIG. 12 illustrates a block diagram of an apparatus having means forinterference mitigation in a wireless communication system.

FIG. 13 illustrates a block diagram of an apparatus having means forinterference mitigation in a heterogeneous wireless communicationsystem.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that the variousaspects may be practiced without these specific details. In otherinstances, well-known structures and devices are shown in block diagramform in order to facilitate describing these aspects.

In FIG. 1, in a communication system 100, a Closed Subscription Group(CSG) cell 102 provides interference mitigation by reduced uplinkbandwidth. In particular, in such CSG deployments, Downlink (DL) blanksubframes 103 enable a non-allowed User Equipment (UE) 104 to co-existwith an allowed UE 106 to CSG cells 102 on a same downlink carrier 108.

Uplink (UL) blank subframes 110 are specified to orthogonalizetransmissions on an UL 112 by the non-allowed UE 104 and allowed UE 106.In an exemplary aspect, this could be done either via explicit UL blanksubframe definition 114 or, in the alternative, derived from DL blanksubframe definition 116.

In the case where no clean UL blank subframes are defined, a scheduler118 of a node 120 (e.g., femto cell, Home evolved Base Node (HeNB),etc.) of the CSG cell 102 schedules the allowed UE 106 in order toorthogonalize data transmissions. However, the Physical Uplink ControlChannel (PUCCH) residual interference 122 from a non-allowed UE 104could be very high and desense a close by HeNB 120.

The CSG cell 102 can avoid this situation by temporarily reducing the ULBandwidth (BW), as depicted at 124. The advertised system BW could staythe same, but a PUCCH 126 by the allowed UE 106 could be moved furtherinside once high interference 128 is detected. With a few connected UEs106 in the case of a femto cell 120, this would work.

One implementation to reduce UL bandwidth is to change an analog filter130, size 132 of a Fast Fourier Transform (FFT) 134, etc to exclude theband edge interference. There could be different alternateimplementations. The FFT size can stay the same but there needs to besome filtering, either analog or digital (i.e., A/D quantizationpermitting). In an illustrative prototype, this may be done with simplyreloading the filter coefficients without any real Hardware (HW) change.

Thus, in an exemplary aspect, an apparatus such as the CSG cell 102 isprovided for interference mitigation in a wireless communication system.The scheduler 118 schedules the UE 106 via a transmitter (TX) 136 to usethe uplink 112 having a first bandwidth. A computing platform 138defines a band edge portion of the first bandwidth that includes aninterference signal. The scheduler 118 further schedules a reducedportion of an uplink bandwidth via the transmitter 136 to the UE 106that avoids the band edge portion. A receiver (RX) 140 receives thereduced portion of the uplink bandwidth by filtering out the band edgeportion.

In FIG. 1B, a network 150 is depicted for UL Hybrid Automatic RepeatRequest (HARQ) process allocation for Random Access Channel (RACH)support. An apparatus, depicted as UE 152, has a receiver (RX) 154 and atransmitter (TX) 156 for interacting with an access node 158 via adownlink 160 and uplink 162 respectively. At least one of the downlink160 and uplink 162 rely upon a relay 164. The UE 152 has a computingplatform 166 that determines a half duplex schedule 168 of performingnon-simultaneous receiving and transmitting by the relay 164 with theaccess node 158. The computing platform 166 further determines aPhysical Random Access Channel (PRACH) configuration having a randomaccess channel occasion that coincides with the half duplex schedule168. Thereby, the UE 152 can utilize the transmitter 156 and thereceiver 154 for performing a random access channel procedure with theaccess node 158 via the relay 164 by using the physical random accesschannel configuration.

In an exemplary aspect, without knowledge of UL blank subframeconfiguration, a relay could configure RACH occasion to coincide withthe non-blank UL subframes as much as possible. With this design, theknowledge of RACH occasion is sufficient for an UE to start RACH andhand over procedure. Note that RACH occasion has 10 and 20 msperiodicity as shown in TABLE 1 below.

The 10 ms periodicity could be supported by assigning all odd/even ULHARQ interlaces to relay. Not all RACH configurations could be supported(such as, for example, 6, 7, 9), because the RACH opportunity spans allUL interlaces. In these cases, there will be some puncturing on RACHoccasions. Note that the annotated entries correspond to the ULsubframes (4, 8, 9, 3) that map to the DL (0, 4, 5, 9) subframes, whichis always available on the access link. The annotated entries are forPhysical Research Access Channel (PRACH) Configuration Index 1, 4, 8(subframe numbers 3, 8); Index 10 (subframe 8), Index 11 (subframe 3,9), Index 12 (subframe 4), Index 14 (subframe 4), and Indices 15, 17 and20. As one example, Configuration (“Config”) 12 could be supported byassigning 4 HARQ processes that map to even subframes to the accesslink.

The 20 ms periodicity could be supported by assigning any of the ¼ ULHARQ interlaces to relay. For example Config 0 could be supported byassigning two UL HARQ processes that include subframes {1, 9, 17, 25,33} and {5, 13, 21, 29, 37} to the access link. In this case, all RACHoccasions occur on the access link UL subframes.

In TABLE 1, an exemplary frame structure type 1 random accessconfiguration is depicted for preamble format 0-3.

TABLE 1 PRACH System Configuration Preamble frame Subframe Index Formatnumber number 0 0 Even 1 1 0 Even 4 2 0 Even 7 3 0 Any 1 4 0 Any 4 5 0Any 7 6 0 Any 1, 6 7 0 Any 2, 7 8 0 Any 3, 8 9 0 Any 1, 4, 7 10 0 Any 2,5, 8 11 0 Any 3, 6, 9 12 0 Any 0, 2, 4, 6, 8 13 0 Any 1, 3, 5, 7, 9 14 0Any 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 15 0 Even 9 16 1 Even 1 17 1 Even 4 181 Even 7 19 1 Any 1 20 1 Any 4 21 1 Any 7 22 1 Any 1, 6 23 1 Any 2, 7 241 Any 3, 8 25 1 Any 1, 4, 7 26 1 Any 2, 5, 8 27 1 Any 3, 6, 9 28 1 Any0, 2, 4, 6, 8 29 1 Any 1, 3, 5, 7, 9 30 N/A N/A N/A 31 1 Even 9 32 2Even 1 33 2 Even 4 34 2 Even 7 35 2 Any 1 36 2 Any 4 37 2 Any 7 38 2 Any1, 6 39 2 Any 2, 7 40 2 Any 3, 8 41 2 Any 1, 4, 7 42 2 Any 2, 5, 8 43 2Any 3, 6, 9 44 2 Any 0, 2, 4, 6, 8 45 2 Any 1, 3, 5, 7, 9 46 N/A N/A N/A47 2 Even 9 48 3 Even 1 49 3 Even 4 50 3 Even 7 51 3 Any 1 52 3 Any 4 533 Any 7 54 3 Any 1, 6 55 3 Any 2, 7 56 3 Any 3, 8 57 3 Any 1, 4, 7 58 3Any 2, 5, 8 59 3 Any 3, 6, 9 60 N/A N/A N/A 61 N/A N/A N/A 62 N/A N/AN/A 63 3 Even 9

In some aspects the teachings herein may be employed in a network thatincludes macro scale coverage (e.g., a large area cellular network suchas a 3G or 4G network, typically referred to as a macro cell network)and smaller scale coverage (e.g., a residence-based or building-basednetwork environment). As an access terminal (“AT”) moves through such anetwork, the access terminal may be served in certain locations byaccess nodes (“ANs”) that provide macro coverage while the accessterminal may be served at other locations by access nodes that providesmaller scale coverage. In some aspects, the smaller coverage nodes maybe used to provide incremental capacity growth, in-building coverage,and different services (e.g., for a more robust user experience). In thediscussion herein, a node that provides coverage over a relatively largearea may be referred to as a macro node. A node that provides coverageover a relatively small area (e.g., a residence) may be referred to as afemto node. A node that provides coverage over an area that is smallerthan a macro area and larger than a femto area may be referred to as apico node (e.g., providing coverage within a commercial building).

A cell associated with a macro node, a femto node, or a pico node may bereferred to as a macro cell, a femto cell, or a pico cell, respectively.In some implementations, each cell may be further associated with (e.g.,divided into) one or more sectors.

In various applications, other terminology may be used to reference amacro node, a femto node, or a pico node. For example, a macro node maybe configured or referred to as an access node, base station, accesspoint, eNodeB, macro cell, and so on. Also, a femto node may beconfigured or referred to as a Home NodeB, Home eNodeB, access pointbase station, femto cell, and so on.

FIG. 2 illustrates a wireless communication system 200, configured tosupport a number of users, in which the teachings herein may beimplemented. The system 200 provides communication for multiple cells202, such as, for example, macro cells 202 a-202 g, with each cell beingserviced by a corresponding access node 204 (e.g., access nodes 204a-204 g). As shown in FIG. 2, access terminals 206 (e.g., accessterminals 206 a-206 l) may be dispersed at various locations throughoutthe system over time. Each access terminal 206 may communicate with oneor more access nodes 204 on a forward link (“FL”) and/or a reverse link(“RL) at a given moment, depending upon whether the access terminal 206is active and whether it is in soft handoff, for example. The wirelesscommunication system 200 may provide service over a large geographicregion. For example, macro cells 202 a-202 g may cover a few blocks in aneighborhood.

In the example shown in FIG. 3, base stations 310 a, 310 b and 310 c maybe macro base stations for macro cells 302 a, 302 b and 302 c,respectively. Base station 310 x may be a pico base station for a picocell 302 x communicating with terminal 320 x. Base station 310 y may bea femto base station for a femto cell 302 y communicating with terminal320 y. Although not shown in FIG. 3 for simplicity, the macro cells mayoverlap at the edges. The pico and femto cells may be located within themacro cells (as shown in FIG. 3) or may overlap with macro cells and/orother cells.

Wireless network 300 may also include relay stations, e.g., a relaystation 310 z that communicates with terminal 320 z. A relay station isa station that receives a transmission of data and/or other informationfrom an upstream station and sends a transmission of the data and/orother information to a downstream station. The upstream station may be abase station, another relay station, or a terminal. The downstreamstation may be a terminal, another relay station, or a base station. Arelay station may also be a terminal that relays transmissions for otherterminals. A relay station may transmit and/or receive low reusepreambles. For example, a relay station may transmit a low reusepreamble in similar manner as a pico base station and may receive lowreuse preambles in similar manner as a terminal.

A network controller 330 may couple to a set of base stations andprovide coordination and control for these base stations. Networkcontroller 330 may be a single network entity or a collection of networkentities. Network controller 330 may communicate with base stations 310via a backhaul. Backhaul network communication 334 can facilitatepoint-to-point communication between base stations 310 a-310 c employingsuch a distributed architecture. Base stations 310 a-310 c may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

Wireless network 300 may be a homogeneous network that includes onlymacro base stations (not shown in FIG. 3). Wireless network 300 may alsobe a heterogeneous network that includes base stations of differenttypes, e.g., macro base stations, pico base stations, home basestations, relay stations, etc. These different types of base stationsmay have different transmit power levels, different coverage areas, anddifferent impact on interference in wireless network 300. For example,macro base stations may have a high transmit power level (e.g., 20Watts) whereas pico and femto base stations may have a low transmitpower level (e.g., 9 Watt). The techniques described herein may be usedfor homogeneous and heterogeneous networks.

Terminals 320 may be dispersed throughout wireless network 300, and eachterminal may be stationary or mobile. A terminal may also be referred toas an access terminal (AT), a mobile station (MS), user equipment (UE),a subscriber unit, a station, etc. A terminal may be a cellular phone, apersonal digital assistant (PDA), a wireless modem, a wirelesscommunication device, a handheld device, a laptop computer, a cordlessphone, a wireless local loop (WLL) station, etc. A terminal maycommunicate with a base station via the downlink and uplink. Thedownlink (or forward link) refers to the communication link from thebase station to the terminal, and the uplink (or reverse link) refers tothe communication link from the terminal to the base station.

A terminal may be able to communicate with macro base stations, picobase stations, femto base stations, and/or other types of base stations.In FIG. 3, a solid line with double arrows indicates desiredtransmissions between a terminal and a serving base station, which is abase station designated to serve the terminal on the downlink and/oruplink. A dashed line with double arrows indicates interferingtransmissions between a terminal and a base station. An interfering basestation is a base station causing interference to a terminal on thedownlink and/or observing interference from the terminal on the uplink.

Wireless network 300 may support synchronous or asynchronous operation.For synchronous operation, the base stations may have the same frametiming, and transmissions from different base stations may be aligned intime. For asynchronous operation, the base stations may have differentframe timing, and transmissions from different base stations may not bealigned in time. Asynchronous operation may be more common for pico andfemto base stations, which may be deployed indoors and may not haveaccess to a synchronizing source such as a Global Positioning System(GPS).

In one aspect, to improve system capacity, the coverage area 302 a, 302b, or 302 c corresponding to a respective base station 310 a-310 c canbe partitioned into multiple smaller areas (e.g., areas 304 a, 304 b,and 304 c). Each of the smaller areas 304 a, 304 b, and 304 c can beserved by a respective base transceiver subsystem (BTS, not shown). Asused herein and generally in the art, the term “sector” can refer to aBTS and/or its coverage area depending on the context in which the termis used. In one example, sectors 304 a, 304 b, 304 c in a cell 302 a,302 b, 302 c can be formed by groups of antennas (not shown) at basestation 310, where each group of antennas is responsible forcommunication with terminals 320 in a portion of the cell 302 a, 302 b,or 302 c. For example, a base station 310 serving cell 302 a can have afirst antenna group corresponding to sector 304 a, a second antennagroup corresponding to sector 304 b, and a third antenna groupcorresponding to sector 304 c. However, it should be appreciated thatthe various aspects disclosed herein can be used in a system havingsectorized and/or unsectorized cells. Further, it should be appreciatedthat all suitable wireless communication networks having any number ofsectorized and/or unsectorized cells are intended to fall within thescope of the hereto appended claims. For simplicity, the term “basestation” as used herein can refer both to a station that serves a sectoras well as a station that serves a cell. It should be appreciated thatas used herein, a downlink sector in a disjoint link scenario is aneighbor sector. While the following description generally relates to asystem in which each terminal communicates with one serving access pointfor simplicity, it should be appreciated that terminals can communicatewith any number of serving access points.

FIG. 4 illustrates an exemplary communication system 400 where one ormore femto nodes are deployed within a network environment.Specifically, the system 400 includes multiple femto nodes, depicted asHome Base Nodes (HNBs) 402 a and 402 b, installed in a relatively smallscale network environment (e.g., in one or more user residences 404).Each femto node 402 a-402 b may be coupled to a wide area network 406(e.g., the Internet) and a mobile operator core network 408 via a DSLrouter, a cable modem, a wireless link, or other connectivity means (notshown). As will be discussed below, each femto node 402 a-402 b may beconfigured to serve associated access terminals or user equipment (UE)410 a and, optionally, alien access UEs 410 b (e.g., not a subscriber toa closed subscriber group). In other words, access to femto nodes 402a-402 b may be restricted whereby a given UE 410 a-410 b may be servedby a set of designated (e.g., home) femto node(s) 402 a-402 b but maynot be served by any non-designated femto nodes 402 a-402 b (e.g., aneighbor's femto node 402 a-402 b).

The owner of a femto node 410 may subscribe to mobile service, such as,for example, 3G mobile service, offered through the mobile operator corenetwork 408. In addition, an access terminal or UE 410 a-410 b may becapable of operating both in macro environments and in smaller scale(e.g., residential) network environments. In other words, depending onthe current location of the UE 410 a-410 b, the access terminal 410a-410 b may be served by an access node or macro base node 412 of themacro cell mobile network 408 or by any one of a set of femto nodes 410(e.g., the femto nodes 402 a-402 b that reside within a correspondinguser residence 404). For example, when a subscriber is outside his home,he is served by a standard macro access node (e.g., node 412) and whenthe subscriber is at home, he is served by a femto node (e.g., node 402a-402 b). Here, it should be appreciated that a femto node 402 a-402 bmay be backward compatible with existing access terminals or UEs 410a-410 b.

A femto node 402 a-402 b may be deployed on a single frequency or, inthe alternative, on multiple frequencies. Depending on the particularconfiguration, the single frequency or one or more of the multiplefrequencies may overlap with one or more frequencies used by a macronode (e.g., node 412).

In some aspects, an access terminal or UE 410 a-410 b may be configuredto connect to a preferred femto node (e.g., the home femto node of theaccess terminal or UE 410 a-410 b) whenever such connectivity ispossible. For example, whenever the access terminal or UE 410 a-410 b iswithin the user's residence 404, it may be desired that the accessterminal or UE 410 a-410 b communicate only with the home femto node 402a-402 b.

In some aspects, if the access terminal or UE 410 a-410 b operateswithin the macro cellular network 408 but is not residing on its mostpreferred network (e.g., as defined in a preferred roaming list), theaccess terminal or UE 410 a-410 b may continue to search for the mostpreferred network (e.g., the preferred femto node 402 a-402 b) using aBetter System Reselection (“BSR”), which may involve a periodic scanningof available systems to determine whether better systems are currentlyavailable, and subsequent efforts to associate with such preferredsystems. With the acquisition entry, the access terminal or UE 410 a-410b may limit the search for specific band and channel. For example, thesearch for the most preferred system may be repeated periodically. Upondiscovery of a preferred femto node 402 a-402 b, the access terminal 410a-410 b selects the femto node 402 a-402 b for camping within itscoverage area.

A femto node may be restricted in some aspects. For example, a givenfemto node may only provide certain services to certain accessterminals. In deployments with so-called restricted (or closed)association, a given access terminal may only be served by the macrocell mobile network and a defined set of femto nodes (e.g., the femtonodes 402 a-402 b that reside within the corresponding user residence404). In some implementations, a node may be restricted to not provide,for at least one node, at least one of: signaling, data access,registration, paging, or service.

In some aspects, a restricted femto node (which may also be referred toas a Closed Subscriber Group Home NodeB) is one that provides service toa restricted provisioned set of access terminals. This set may betemporarily or permanently extended as necessary. In some aspects, aClosed Subscriber Group (“CSG”) may be defined as the set of accessnodes (e.g., femto nodes) that share a common access control list ofaccess terminals. A channel on which all femto nodes (or all restrictedfemto nodes) in a region operate may be referred to as a femto channel.

Various relationships may thus exist between a given femto node and agiven access terminal or user equipment. For example, from theperspective of an access terminal, an open femto node may refer to afemto node with no restricted association. A restricted femto node mayrefer to a femto node that is restricted in some manner (e.g.,restricted for association and/or registration). A home femto node mayrefer to a femto node on which the access terminal is authorized toaccess and operate on. A guest femto node may refer to a femto node onwhich an access terminal is temporarily authorized to access or operateon. An alien femto node may refer to a femto node on which the accessterminal is not authorized to access or operate on, except for perhapsemergency situations (e.g., 911 calls).

From a restricted femto node perspective, a home access terminal mayrefer to an access terminal that authorized to access the restrictedfemto node. A guest access terminal may refer to an access terminal withtemporary access to the restricted femto node. An alien access terminalmay refer to an access terminal that does not have permission to accessthe restricted femto node, except for perhaps emergency situations, forexample, such as 911 calls (e.g., an access terminal that does not havethe credentials or permission to register with the restricted femtonode).

For convenience, the disclosure herein describes various functionalityin the context of a femto node. It should be appreciated, however, thata pico node may provide the same or similar functionality for a largercoverage area. For example, a pico node may be restricted; a home piconode may be defined for a given access terminal, and so on.

A wireless multiple-access communication system may simultaneouslysupport communication for multiple wireless access terminals. Asmentioned above, each terminal may communicate with one or more basestations via transmissions on the forward and reverse links. The forwardlink (or downlink) refers to the communication link from the basestations to the terminals, and the reverse link (or uplink) refers tothe communication link from the terminals to the base stations. Thiscommunication link may be established via a single-in-single-out system,a multiple-in-multiple-out (“MIMO”) system, or some other type ofsystem.

FIG. 5 illustrates an example of a coverage map 500 where severaltracking areas 502 (or routing areas or location areas) are defined,each of which includes several macro coverage areas 504. Here, areas ofcoverage associated with tracking areas 502 a, 502 b, and 502 c aredelineated by the wide lines and the macro coverage areas 504 arerepresented by the hexagons. The tracking areas 502 also include femtocoverage areas 506. In this example, each of the femto coverage areas506 (e.g., femto coverage area 506 c) is depicted within a macrocoverage area 504 (e.g., macro coverage area 504 b). It should beappreciated, however, that a femto coverage area 506 may not lieentirely within a macro coverage area 504. In practice, a large numberof femto coverage areas 506 may be defined with a given tracking area502 or macro coverage area 504. Also, one or more pico coverage areas(not shown) may be defined within a given tracking area 502 or macrocoverage area 504.

Referring to FIG. 6, a multiple access wireless communication systemaccording to one aspect is illustrated. An access point (AP) 600includes multiple antenna groups, one including 606 and 606, anotherincluding 608 and 610, and an additional including 612 and 614. In FIG.6, only two antennas are shown for each antenna group, however, more orfewer antennas may be utilized for each antenna group. Access terminal(AT) 616 is in communication with antennas 612 and 614, where antennas612 and 614 transmit information to access terminal 616 over forwardlink 620 and receive information from access terminal 616 over reverselink 618. Access terminal 622 is in communication with antennas 606 and608, where antennas 606 and 608 transmit information to access terminal622 over forward link 626 and receive information from access terminal622 over reverse link 624. In a FDD system, communication links 618,620, 624 and 626 may use different frequencies for communication. Forexample, forward link 620 may use a different frequency then that usedby reverse link 618.

Each group of antennas and/or the area in which they are designed tocommunicate is often referred to as a sector of the access point. In theaspect, antenna groups each are designed to communicate to accessterminals in a sector, of the areas covered by access point 600.

In communication over forward links 620 and 626, the transmittingantennas of access point 600 utilize beamforming in order to improve thesignal-to-noise ratio of forward links for the different accessterminals 616 and 622. Also, an access point using beamforming totransmit to access terminals scattered randomly through its coveragecauses less interference to access terminals in neighboring cells thanan access point transmitting through a single antenna to all of itsaccess terminals.

An access point may be a fixed station used for communicating with theterminals and may also be referred to as an access point, a Node B, orsome other terminology. An access terminal may also be called userequipment (UE), a wireless communication device, terminal, or some otherterminology.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and N_(R) receive antennas may be decomposed intoN_(S) independent channels, which are also referred to as spatialchannels, where N_(S)≦min{N_(T), N_(R)}. Each of the N_(S) independentchannels corresponds to a dimension. The MIMO system may provideimproved performance (e.g., higher throughput and/or greaterreliability) if the additional dimensionalities created by the multipletransmit and receive antennas are utilized.

A MIMO system may support time division duplex (“TDD”) and frequencydivision duplex (“FDD”). In a TDD system, the forward and reverse linktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the forward link channel from thereverse link channel. This enables the access point to extract transmitbeam-forming gain on the forward link when multiple antennas areavailable at the access point.

The teachings herein may be incorporated into a node (e.g., a device)employing various components for communicating with at least one othernode. FIG. 7 depicts several sample components that may be employed tofacilitate communication between nodes. Specifically, FIG. 7 illustratesa wireless device 710 (e.g., an access point) and a wireless device 750(e.g., an access terminal) of a MIMO system 700. At the device 710,traffic data for a number of data streams is provided from a data source712 to a transmit (“TX”) data processor 714.

In some aspects, each data stream is transmitted over a respectivetransmit antenna. The TX data processor 714 formats, codes, andinterleaves the traffic data for each data stream based on a particularcoding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by a processor 730. A data memory 732 may storeprogram code, data, and other information used by the processor 730 orother components of the device 710.

The modulation symbols for all data streams are then provided to a TXMIMO processor 720, which may further process the modulation symbols(e.g., for OFDM). The TX MIMO processor 720 then provides N_(T)modulation symbol streams to N_(T) transceivers (“XCVR”) 722 a through722 t that each has a transmitter (TMTR) and receiver (RCVR). In someaspects, the TX MIMO processor 720 applies beam-forming weights to thesymbols of the data streams and to the antenna from which the symbol isbeing transmitted.

Each transceiver 722 a-722 t receives and processes a respective symbolstream to provide one or more analog signals, and further conditions(e.g., amplifies, filters, and upconverts) the analog signals to providea modulated signal suitable for transmission over the MIMO channel.N_(T) modulated signals from transceivers 722 a through 722 t are thentransmitted from N_(T) antennas 724 a through 724 t, respectively.

At the device 750, the transmitted modulated signals are received byN_(R) antennas 752 a through 752 r and the received signal from eachantenna 752 a-752 r is provided to a respective transceiver (“XCVR”) 754a through 754 r. Each transceiver 754 a-754 r conditions (e.g., filters,amplifies, and downconverts) a respective received signal, digitizes theconditioned signal to provide samples, and further processes the samplesto provide a corresponding “received” symbol stream.

A receive (“RX”) data processor 760 then receives and processes theN_(R) received symbol streams from N_(R) transceivers 754 a-754 r basedon a particular receiver processing technique to provide N_(T)“detected” symbol streams. The RX data processor 760 then demodulates,deinterleaves, and decodes each detected symbol stream to recover thetraffic data for the data stream. The processing by the RX dataprocessor 760 is complementary to that performed by the TX MIMOprocessor 720 and the TX data processor 714 at the device 710.

A processor 770 periodically determines which pre-coding matrix to use.The processor 770 formulates a reverse link message comprising a matrixindex portion and a rank value portion. A data memory 772 may storeprogram code, data, and other information used by the processor 770 orother components of the device 750.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 738, whichalso receives traffic data for a number of data streams from a datasource 736, modulated by a modulator 780, conditioned by thetransceivers 754 a through 754 r, and transmitted back to the device710.

At the device 710, the modulated signals from the device 750 arereceived by the antennas 724 a-724 t, conditioned by the transceivers722 a-722 t, demodulated by a demodulator (“DEMOD”) 740, and processedby a RX data processor 742 to extract the reverse link messagetransmitted by the device 750. The processor 730 then determines whichpre-coding matrix to use for determining the beam-forming weights thenprocesses the extracted message.

FIG. 7 also illustrates that the communication components may includeone or more components that perform interference control operations. Forexample, an interference (“INTER.”) control component 790 may cooperatewith the processor 730 and/or other components of the device 710 tosend/receive signals to/from another device (e.g., device 750).Similarly, an interference control component 792 may cooperate with theprocessor 770 and/or other components of the device 750 to send/receivesignals to/from another device (e.g., device 710). It should beappreciated that for each device 710 and 750 the functionality of two ormore of the described components may be provided by a single component.For example, a single processing component may provide the functionalityof the interference control component 790 and the processor 730 and asingle processing component may provide the functionality of theinterference control component 792 and the processor 770.

In FIG. 8, a methodology or sequence of operations 800 is depicted forinterference mitigation in a wireless communication system bydetermining a half duplex schedule of performing non-simultaneousreceiving and transmitting by a relay with an access node (block 804),determining a physical random access channel configuration having arandom access channel occasion that coincides with the half duplexschedule (block 806), and performing a random access channel procedurewith the access node via the relay by using the physical random accesschannel configuration (block 808).

In FIG. 9, a methodology or sequence of operations 900 is depicted forinterference mitigation in a heterogeneous wireless communication systemby scheduling a user equipment to use an uplink having a first bandwidth(block 904), defining a band edge portion of the first bandwidth thatincludes an interference signal (block 906), scheduling a reducedportion of an uplink bandwidth to the user equipment that avoids theband edge portion (block 908), and receiving the reduced portion of theuplink bandwidth by filtering out the band edge portion (block 910).

With reference to FIG. 10, illustrated is a system 1000 for interferencemitigation in a wireless communication system. For example, system 1000can reside at least partially within user equipment (UE). It is to beappreciated that system 1000 is represented as including functionalblocks, which can be functional blocks that represent functionsimplemented by a computing platform, processor, software, or combinationthereof (e.g., firmware). System 1000 includes a logical grouping 1002of electrical components that can act in conjunction. For instance,logical grouping 1002 can include an electrical component fordetermining a half duplex schedule of performing non-simultaneousreceiving and transmitting by a relay with an access node 1004.Moreover, logical grouping 1002 can include an electrical component fordetermining a physical random access channel configuration having arandom access channel occasion that coincides with the half duplexschedule 1006. For another instance, logical grouping 1002 can includean electrical component for performing a random access channel procedurewith the access node via the relay by using the physical random accesschannel configuration 1008. Additionally, system 1000 can include amemory 1020 that retains instructions for executing functions associatedwith electrical components 1004-1008. While shown as being external tomemory 1020, it is to be understood that one or more of electricalcomponents 1004-1008 can exist within memory 1020.

With reference to FIG. 11, illustrated is a system 1100 for interferencemitigation in a wireless communication system. For example, system 1100can reside at least partially within user equipment (UE). It is to beappreciated that system 1100 is represented as including functionalblocks, which can be functional blocks that represent functionsimplemented by a computing platform, processor, software, or combinationthereof (e.g., firmware). System 1100 includes a logical grouping 1102of electrical components that can act in conjunction. For instance,logical grouping 1102 can include an electrical component for schedulinga user equipment to use an uplink having a first bandwidth 1104.Moreover, logical grouping 1102 can include an electrical component fordefining a band edge portion of the first bandwidth that includes aninterference signal 1106. For another instance, logical grouping 1102can include an electrical component for scheduling a reduced portion ofan uplink bandwidth to the user equipment that avoids the band edgeportion 1108. For an additional instance, logical grouping 1102 caninclude an electrical component for receiving the reduced portion of theuplink bandwidth by filtering out the band edge portion 1110.Additionally, system 1100 can include a memory 1120 that retainsinstructions for executing functions associated with electricalcomponents 1104-1110. While shown as being external to memory 1120, itis to be understood that one or more of electrical components 1104-1110can exist within memory 1120.

In FIG. 12, an apparatus 1202 is depicted for interference mitigation ina wireless communication system. Means 1204 are provided for determininga half duplex schedule of performing non-simultaneous receiving andtransmitting by a relay with an access node. Means 1206 are provided fordetermining a physical random access channel configuration having arandom access channel occasion that coincides with the half duplexschedule. Means 1208 are provided for performing a random access channelprocedure with the access node via the relay by using the physicalrandom access channel configuration.

In FIG. 13, an apparatus 1302 is depicted for interference mitigation ina heterogeneous wireless communication system. Means 1304 are providedfor scheduling a user equipment to use an uplink having a firstbandwidth. Means 1306 are provided for defining a band edge portion ofthe first bandwidth that includes an interference signal. Means 1308 areprovided for scheduling a reduced portion of an uplink bandwidth to theuser equipment that avoids the band edge portion. Means 1310 areprovided for receiving the reduced portion of the uplink bandwidth byfiltering out the band edge portion.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the aspects disclosed herein may be implemented aselectronic hardware, computer software, or combinations of both. Toclearly illustrate this interchangeability of hardware and software,various illustrative components, blocks, modules, circuits, and stepshave been described above generally in terms of their functionality.Whether such functionality is implemented as hardware or softwaredepends upon the particular application and design constraints imposedon the overall system. Skilled artisans may implement the describedfunctionality in varying ways for each particular application, but suchimplementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

As used in this application, the terms “component”, “module”, “system”,and the like are intended to refer to a computer-related entity, eitherhardware, a combination of hardware and software, software, or softwarein execution. For example, a component may be, but is not limited tobeing, a process running on a processor, a processor, an object, anexecutable, a thread of execution, a program, and/or a computer. By wayof illustration, both an application running on a server and the servercan be a component. One or more components may reside within a processand/or thread of execution and a component may be localized on onecomputer and/or distributed between two or more computers.

The word “exemplary” is used herein to mean serving as an example,instance, or illustration. Any aspect or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs.

Various aspects will be presented in terms of systems that may include anumber of components, modules, and the like. It is to be understood andappreciated that the various systems may include additional components,modules, etc. and/or may not include all of the components, modules,etc. discussed in connection with the figures. A combination of theseapproaches may also be used. The various aspects disclosed herein can beperformed on electrical devices including devices that utilize touchscreen display technologies and/or mouse-and-keyboard type interfaces.Examples of such devices include computers (desktop and mobile), smartphones, personal digital assistants (PDAs), and other electronic devicesboth wired and wireless.

In addition, the various illustrative logical blocks, modules, andcircuits described in connection with the aspects disclosed herein maybe implemented or performed with a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

Furthermore, the one or more versions may be implemented as a method,apparatus, or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware, or anycombination thereof to control a computer to implement the disclosedaspects. The term “article of manufacture” (or alternatively, “computerprogram product”) as used herein is intended to encompass a computerprogram accessible from any computer-readable device, carrier, or media.For example, computer readable media can include but are not limited tomagnetic storage devices (e.g., hard disk, floppy disk, magnetic strips. . . ), optical disks (e.g., compact disk (CD), digital versatile disk(DVD) . . . ), smart cards, and flash memory devices (e.g., card,stick). Additionally it should be appreciated that a carrier wave can beemployed to carry computer-readable electronic data such as those usedin transmitting and receiving electronic mail or in accessing a networksuch as the Internet or a local area network (LAN). Of course, thoseskilled in the art will recognize many modifications may be made to thisconfiguration without departing from the scope of the disclosed aspects.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such the processorcan read information from, and write information to, the storage medium.In the alternative, the storage medium may be integral to the processor.The processor and the storage medium may reside in an ASIC. The ASIC mayreside in a user terminal. In the alternative, the processor and thestorage medium may reside as discrete components in a user terminal.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other embodiments without departing from the spirit or scopeof the disclosure. Thus, the present disclosure is not intended to belimited to the embodiments shown herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

In view of the exemplary systems described supra, methodologies that maybe implemented in accordance with the disclosed subject matter have beendescribed with reference to several flow diagrams. While for purposes ofsimplicity of explanation, the methodologies are shown and described asa series of blocks, it is to be understood and appreciated that theclaimed subject matter is not limited by the order of the blocks, assome blocks may occur in different orders and/or concurrently with otherblocks from what is depicted and described herein. Moreover, not allillustrated blocks may be required to implement the methodologiesdescribed herein. Additionally, it should be further appreciated thatthe methodologies disclosed herein are capable of being stored on anarticle of manufacture to facilitate transporting and transferring suchmethodologies to computers. The term article of manufacture, as usedherein, is intended to encompass a computer program accessible from anycomputer-readable device, carrier, or media.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein, will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

What is claimed is:
 1. A method for interference mitigation in awireless communication system at a base station, the method comprising:advertising an uplink bandwidth; identifying that a band edge portion ofthe uplink bandwidth includes an interfering signal of an interferinguser equipment (UE); scheduling a served UE to use a reduced uplinkbandwidth that avoids the band edge portion based on the identifying;receiving a transmission from the served UE in the reduced uplinkbandwidth; and filtering out the band edge portion.
 2. The method ofclaim 1, further comprising scheduling the served UE to use theadvertised uplink bandwidth in response to detecting an absence of theinterfering signal.
 3. The method of claim 1, wherein scheduling theserved UE to use the reduced uplink bandwidth comprises scheduling theserved UE to transmit the uplink control channel closer to the center ofthe advertised bandwidth.
 4. The method of claim 1, further comprisingdetermining there are no uplink (UL) blank subframes defined, whereinthe UL blank subframes are subframes to orthogonalize transmissions on aUL by interfering UEs and served UEs;
 5. The method of claim 4, whereinthe determining comprises: accessing a downlink frame structure, thedownlink frame structure being capable of identifying a plurality ofdownlink subframes that have a blank portion; and determining an uplinkframe structure based on the downlink frame structure.
 6. The method ofclaim 4, wherein the determining comprises accessing an explicit uplinksubframe definition.
 7. The method of claim 4, wherein the determiningcomprises deriving the uplink subframe definition.
 8. The method ofclaim 1, further comprising authenticating the served UE on a closedsubscription group cell.
 9. The method of claim 1, wherein the filteringcomprises: performing analog-to-digital sampling of a received signalsufficient to separate the band edge portion from the reduced portion;and changing digital filter coefficients to attenuate the band edgeportion.
 10. The method of claim 1, wherein the filtering comprisesanalog filtering.
 11. A computer program product stored on anon-transitory computer readable medium comprising code for causing atleast one processor to: advertise an uplink bandwidth; identify that aband edge portion of the uplink bandwidth includes an interfering signalof an interfering user equipment (UE); schedule a served UE to use areduced uplink bandwidth that avoids the band edge portion based on theidentifying; receive a transmission from the served UE in the reduceduplink bandwidth; and filter out the band edge portion.
 12. An apparatusfor interference mitigation in a wireless communication system, theapparatus comprising: means for advertising an uplink bandwidth; meansfor identifying that a band edge portion of the uplink bandwidthincludes an interfering signal of an interfering user equipment (UE);means for scheduling a served UE to use a reduced uplink bandwidth thatavoids the band edge portion based on the identifying; means forreceiving a transmission from the served UE in the reduced uplinkbandwidth; and means for filtering out the band edge portion.
 13. Anapparatus for interference mitigation in a wireless communicationsystem, the apparatus comprising: a transmitter; a scheduler forscheduling a served user equipment (UE) via the transmitter to use anuplink having an uplink bandwidth in a frame; a computing platform for:advertising the uplink bandwidth; identifying that a band edge portionof the uplink bandwidth includes an interfering signal of an interferingUE; the scheduler further for scheduling the served UE to use a reduceduplink bandwidth that avoids the band edge portion based on theidentifying; and a receiver for: receiving a transmission from theserved UE in the reduced uplink bandwidth, and filtering out the bandedge portion.
 14. The apparatus of claim 13, wherein the scheduler isfurther for scheduling the served UE to use the advertised uplinkbandwidth in response to detecting an absence of the interfering signal.15. The apparatus of claim 13, wherein the scheduling the served UE touse the reduced uplink bandwidth comprises scheduling the served UE totransmit the uplink control channel closer to the center of theadvertised bandwidth.
 16. The apparatus of claim 13, wherein thecomputing platform is further for determining there are no uplink (UL)blank subframes defined, wherein the UL blank subframes are subframes toorthogonalize transmissions on a UL by interfering UEs and served UEs;17. The apparatus of claim 16, wherein the determining comprises:accessing a downlink frame structure, the downlink frame structure beingcapable of identifying a plurality of downlink subframes that have ablank portion; and determining an uplink frame structure based on thedownlink frame structure.
 18. The apparatus of claim 16, wherein thedetermining comprises accessing an explicit uplink subframe definition.19. The apparatus of claim 16, wherein the determining comprisesderiving the uplink subframe definition.
 20. The apparatus of claim 13,wherein the computing platform is further for authenticating the servedUE on a closed subscription group cell.
 21. The apparatus of claim 13,wherein the filtering comprises, performing analog-to-digital samplingof a received signal sufficient to separate the band edge portion fromthe reduced portion; and changing digital filter coefficients toattenuate the band edge portion.
 22. The apparatus of claim 13, whereinthe filtering comprises analog filtering.